I can see why that's not a nice feeling but honestly, if you realize this is pretty much an alternative lifestyle, then it should be completely fine when told:

I can see why that's not a nice feeling but honestly, if you realize this is pretty much an alternative lifestyle, then it should be completely fine when told: "hey there's a team dinner", to mention the fact that you are meat-free. What's wrong: if they decide to not care about that. What's right: they accommodate your dietary preferences. Don't think you should put the burden on other people to consider these kinds of things beforehand. It's great if they do, but it's not an issue if they don't.